The Cancer Center Flow Cytometry Shared Resource has been integrated in the Institutional Flow Cytometry Core Facility and has been in existence for 23 years. It is located in room 5.044V at the University of Texas Health Science Center at San Antonio (UTHSCSA) and occupies 800 sq. ft. It is administered through the Office of the Vice President for Research in coordination with the Executive Director of the Cancer Center. It serves >35 Cancer Center members in several campuses including the UTHSCSA the Greehey Children's Cancer Research Institute (GCCRI) and the Institute for Drug Discovery (IDD). Access to the flow lab is available to all investigators in the Cancer Center with priority given to NIHfunded -investigators and Cancer Center members. The Flow Cytometry Shared Resource is based on 3 advanced Becton Dickinson (BD) Flow Cytometers: 1) FACSAria cell sorter/ analyzer, equipped with 3- lasers allowing simultaneous sorting and analysis by up to 13 colors, and simultaneous sorting of 4 different cell populations at a speed of up to 20,000 events/sec. 2) FACStar Plus cell sorter/analyzer, equipped with two lasers, and upgraded through an NIH SIG grant to a TurboSort with sorting of 5,000 events/sec and 4-color analysis, and 3) FACSCalibur analyzer, equipped with 2-lasers. Shared resource personnel include the Director with over 30 years.of experience in flow cytometry and two experienced operators (20 and 4 years). All personnel are Becton-Dickinson certified operators. Services include multicolor sorting and analyses, phenotyping and cloning of subpopulations of lymphocytes, tumor cells, stem cells and cells expressing fluorescent transgene proteins;cell sorting according to cell cycle position; measurements and kinetics of nitric oxide, oxygen peroxide and free radicals, reduced glutathione, pH, Ca++ fluxes and fluxes of different vial dyes;quantitation of multiple cytokines using fluorescent microspheres (CBA/BD);study of mitochondrial damage;determination of multiple activated caspases; consulting services;and assistance in grant writing and publication services. The shared resource supports 26 NIH-funded, P30 members holding 20 NIH grants of over $6 million/year in direct costs. Thirty-nine peer reviewed papers were published by P30 members in 2007-2008 (over 150 publications in the past 5 years) with pertinent use of flow cytometry, attesting to the productivity of the cancer investigators and the integral role flow cytometry plays in their ongoing research projects.